Giant Hogweed

Heracleum mantegazzianum

Common Name: Giant Hogweed
Scientific Name: Heracleum mantegazzianum
Family: Umbelliferae
Growth Form: Herb
Native Range: Asia
Invasive Range: Greatest density in central and western New York, but distributed throughout New England
Introduction: The Giant hogweed was brought to North America as an ornamental and garden curiosity.  It escaped from cultivation and reproduces by seed.
Description: ·Leaves: Compound.  Deeply incised.  Up to 1m (3 ft.) long, 80 cm (35 in.) wide.

·Stem:  Hollow, 4-7 cm (2-4 in.) in diameter, purple blotches, bristles.   2-5m (6-15 ft.) tall. Coarse purple hair at base of leaf stalk.

·Flowers:  White, cluster like convex umbrella, up to 1 m (3 ft) in diameter. 

·Fruit: Schizocarp.  Oval, brown, broad ridge around margin.  Seeds oval, orange, about 10 mm (0.5 in.) long.
Threats: The giant hogweed is incredibly toxic and has the ability to reproduce quickly and escape from cultivation.
Fun Facts: The sap of the giant hogweed causes photo-dermatitis.  Upon exposure to sunlight, the skin blisters and then scars purple or black.  Giant hogweed sap can also cause permanent blindness if it gets in one’s eyes. 
Single flower